Well, as a fan of the series, I did like this one, but it was pretty jam-packed. It's better than the third book for pacing, but it is FAST, so strap in and hold on. It was definitely a fun ride with lots of action.
I love the twists and turns and the heist-like feel; the new storylines opened up are really exciting, too, and this concludes one plotline while setting up an even more exciting continuation. As always, the villains are sympathetic (except for Jewel) and the settings are really interesting. It's also nice that we can get things like an awesome robot fight and a mating bond ritual delivered with a very modern sensibility--this ain't Star Trek, and that's nice to see.
There are a LOT of characters in this one, though, so I can't recommend reading this one first. If you're starting the series, read book 2 first, then book 3, then book 1, then this one. Also, two of my fave characters were barely in this, which made me a bit sad.
Still, I'd recommend it and it's a must for fans of the series. Read it and stay in touch. The next part of the series is going to be a doozy.